Abstract

We consider Lorentzian correlators of local operators. In perturbation theory, singularities occur when we can draw a position-space Landau diagram with null lines. In theories with gravity duals, we can also draw Landau diagrams in the bulk. We argue that certain singularities can arise only from bulk diagrams, not from boundary diagrams. As has been previously observed, these singularities are a clear diagnostic of bulk locality. We analyze some properties of these perturbative singularities and discuss their relation to the OPE and the dimensions of double-trace operators. In the exact nonperturbative theory, we expect no singularity at these locations. We prove this statement in 1+1 dimensions by CFT methods.

Highlights

  • In Euclidean signature, correlators of local operators are analytic for non-coincident points

  • In theories that have gravity duals, singularities can arise from Landau diagrams in the bulk

  • We consider singularities arising from a local bulk. We argue that these singularities do not arise from boundary Landau diagrams in 1+1 and 2+1 dimensions

Read more

Summary

Introduction

In Euclidean signature, correlators of local operators are analytic for non-coincident points. In Lorentzian signature, singularities can arise when “something happens.” These Lorentzian singularities correspond, in weakly coupled theories, to Landau diagrams consisting of a set of null particles interacting at local vertices in an energy-momentum conserving fashion. In theories that have gravity duals, singularities can arise from Landau diagrams in the bulk In some cases, these occur at positions where there is no Landau diagram on the boundary [9,10,11,12,13]. We argue that these singularities do not arise from boundary Landau diagrams in 1+1 and 2+1 dimensions. Other appendices give more details on the discussion in the main body

Singularities of perturbative correlation functions
A four-point function example
From Minkowski space to the cylinder
Applications to symbology
Bulk versus boundary singularities
Bulk-point singularities from a local bulk
Singularities beyond perturbation theory
Stringy corrections
Instanton corrections
General argument for the position dependence of one-instanton corrections
Exact answer
Summary
Singularities of the four-point function
Approaching singularities using the OPE
A simple bound on the bulk-point singularity
Origin of the singularity from the dimensions of operators in the OPE
The Regge limit and the bound on chaos
Other analytic continuations
Conclusions
A Bounds on higher derivative interactions
B Limits of conformal blocks and MFT OPE coefficients
D Transformation to the pillow metric

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.